XM-19, often known by its AK Steel brand name of Nitronic 50®, is a high strength nitrogen-bearing

austenitic stainless steel.

It has superior corrosion resistance and strength compared to 316/316L stainless.

Approximate Composition – 21% Cr, 5.0% Mn, 12.0% Ni, 2.0% Mo, 0.3% N plus Nb and V (vanadium).

Grade 1.3964 does not appear officially in the EN system but is found in SEW 390 as Werkstoff Nummer (W Nr) 1.3964.

XM-19 stainless grade combines the following characteristics:

Better pitting and crevice corrosion resistance than 316/316L and 317L depending on the environment
Good yield strength (415 MPa minimum) in solution annealed condition
Special hot working processes allow yield strength of up to 800 MPa dependent on section size
Extremely high strength by cold drawing
Impact toughness down to cryogenic temperatures. Advantage over high strength duplex grades
Use at up to 580°C. Advantage over duplex grades (300°C maximum)
Non-magnetic even with high levels of cold work
Difficult to machine due to high hardness

XM-19 offers an excellent combination of high strength and corrosion resistance.

Its main advantage over competitive materials like duplex grades is its much wider band of useful

temperatures both at the high and low end of the spectrum. Increased solubility of nitrogen for high

strength is achieved with the high manganese content.

Its non-magnetic properties are vital in specialist applications like submarine hulls and minesweepers.

Applications include:

Offshore oil and gas connectors and couplings, chemical storage vessels, marine drive shafts, pump shafts,

valves, yacht rigging, submarine hulls.